Methyl methacrylate composition

Abstract

The present invention addresses the problem of providing a molded article with good heat resistance. The present invention relates to a methyl methacrylate composition containing regenerated methyl methacrylate and non-regenerated methyl methacrylate, the regenerated methyl methacrylate content being 0.5-99.5% by mass, and the non-regenerated methyl methacrylate content being 0.5-99.5% by mass.

Description

Technical Field

[0001] The present invention relates to a methyl methacrylate composition containing methyl methacrylate as a main component. Background Art

[0002] Polymethyl methacrylate (PMMA), which is a polymer obtained by polymerizing methyl methacrylate (MMA), has excellent transparency and weather resistance, and is therefore widely used as a material constituting components of automobile parts, signboards, display devices, and the like.

[0003] In recent years, with the rise in resource prices and the increase in awareness of environmental issues, there has been a demand for the recovery and reuse (recycling) of polymethyl methacrylate products (molded articles) used for various purposes as described above.

[0004] Examples of methods for recycling polymethyl methacrylate include: material recycling, in which a new molded body is produced by subjecting the recovered molded body to a molding process again; chemical recycling, in which polymethyl methacrylate is thermally decomposed (depolymerized) by heat-treating the recovered molded body to recover methyl methacrylate, and the recovered methyl methacrylate (sometimes referred to as recovered MMA) is used to produce a new molded body; and thermal recycling, in which the recovered molded body is burned as fuel, the combustion energy is directly used as a heat source, and the combustion energy is further used to generate electricity.

[0005] Polymethyl methacrylate is preferably recycled by chemical recycling because methyl methacrylate can be recovered at a high yield and impurities can be reduced by heating at a relatively low temperature of about 300°C.

[0006] In the chemical recycling of acrylic resin waste containing polymethyl methacrylate as a main component, the following technology is known: when depolymerizing by heat treatment using a heating kettle equipped with a stirring device, the tip speed of the stirring blade is focused on and adjusted so that monomers such as methyl methacrylate generated by depolymerization will not be further decomposed and changed, but will be recovered as high-purity monomers (see Patent Document 1).

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2003-321571 Summary of the invention

[0010] Problem that the invention aims to solve

[0011] However, according to the methyl methacrylate obtained by the recovery method according to Patent Document 1, the heat resistance of a molded article obtained by molding a methyl methacrylate composition containing the methyl methacrylate may not be sufficient.

[0012] Solutions for solving problems

[0013] The inventors of the present invention have conducted intensive studies to solve the above problems and have found that the above problems can be solved by adjusting the composition of recycled methyl methacrylate and non-recycled methyl methacrylate in the methyl methacrylate composition, thereby completing the present invention.

[0014] That is, the present invention provides the following [1] to

[12] .

[0015] [1] A methyl methacrylate composition comprising regenerated methyl methacrylate and non-regenerated methyl methacrylate,

[0016] The content of the regenerated methyl methacrylate is 0.5 to 99.5% by mass, and the content of the non-regenerated methyl methacrylate is 0.5 to 99.5% by mass.

[0017] [2] The methyl methacrylate composition according to [1], wherein the regenerated methyl methacrylate is regenerated methyl methacrylate derived from chemical recycling.

[0018] [3] The methyl methacrylate composition according to [1] or [2], wherein the content of the recycled methyl methacrylate is 5 to 40% by mass, and the content of the non-recycled methyl methacrylate is 60 to 95% by mass.

[0019] [4] The methyl methacrylate composition according to any one of [1] to [3], further comprising an alkyl acrylate.

[0020] [5] A method for producing a methyl methacrylate polymer, comprising the step of polymerizing the methyl methacrylate composition according to any one of [1] to [3].

[0021] [6] A methyl methacrylate polymer obtained by polymerizing the methyl methacrylate composition according to any one of [1] to [3].

[0022] [7] A methyl methacrylate polymer comprising structural units derived from recycled methyl methacrylate and structural units derived from non-recycled methyl methacrylate, wherein the content of the structural units derived from recycled methyl methacrylate is 0.5 to 99.5% by mass, and the content of the structural units derived from non-recycled methyl methacrylate is 0.5 to 99.5% by mass.

[0023] [8] A heat resistance-improving agent for a methyl methacrylate polymer comprising non-regenerated methyl methacrylate, the agent comprising, as an active ingredient, a recycled methyl methacrylate product derived from chemical recycling of polymethyl methacrylate.

[0024] [9] The enhancer according to [8], wherein the polymer of the regenerated methyl methacrylate product has a 5% weight reduction temperature of 300°C or higher and / or a glass transition temperature of 90°C or higher.

[0025]

[10] The enhancing agent according to [8] or [9], wherein the polymer of the non-regenerated methyl methacrylate product has a 5% weight reduction temperature of 200°C or higher and / or a glass transition temperature of 105°C or higher.

[0026]

[11] The enhancer according to any one of [8] to

[10] , wherein the polymer of the regenerated methyl methacrylate product has a 5% weight reduction temperature higher than the 5% weight reduction temperature of the non-regenerated methyl methacrylate product, and / or a glass transition temperature lower than the glass transition temperature of the non-regenerated methyl methacrylate product.

[0027]

[12] Use of a recycled methyl methacrylate product derived from chemical recycling of polymethyl methacrylate for producing a heat resistance-improving agent for methyl methacrylate polymers containing non-recycled methyl methacrylate.

[0028] Effects of the Invention

[0029] According to the present invention, a methyl methacrylate polymer obtained by polymerizing a methyl methacrylate composition containing recycled methyl methacrylate including recycled MMA and non-recycled methyl methacrylate, and a molded product thereof can have good heat resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a graph showing the relationship between the ratio of recycled MMA in a molded body of a methyl methacrylate composition using recycled MMA of Production Example 1 and the 5% weight loss temperature. Figure 1 The dotted line in is a straight line connecting the plotted points of Reference Example 1 and Comparative Example 1.

[0031] Figure 2 This is a graph showing the relationship between the ratio of recycled MMA in a molded body of a methyl methacrylate composition using recycled MMA of Preparation Example 1 and the glass transition temperature. Figure 2 The dotted line in is a straight line connecting the plotted points of Reference Example 1 and Comparative Example 1.

[0032] Figure 3 This is a graph showing the relationship between the ratio of each regenerated MMA and the 5% weight loss temperature in a molded article of a methyl methacrylate composition using regenerated MMA (A) to (D). Figure 3 The dotted line in FIG. 1 is a straight line connecting the plotted points of Reference Example 1 and Comparative Example 2 of regenerated MMA (A).

[0033] Figure 4 This is a graph showing the relationship between the ratio of each regenerated MMA and the glass transition temperature in a molded article of a methyl methacrylate composition using regenerated MMA (A) to (D). Figure 3 The dotted line in FIG. 1 is a straight line connecting the plotted points of Reference Example 1 and Comparative Example 5 of regenerated MMA (D). DETAILED DESCRIPTION

[0034] Hereinafter, the embodiments of the present invention will be described in detail. The present invention is not limited to the following description. In addition, each element involved in the embodiments of the present invention can be appropriately changed within the scope of the gist of the present invention.

[0035] 1. Methyl methacrylate composition

[0036] The methyl methacrylate composition of the present embodiment contains recycled methyl methacrylate and non-recycled methyl methacrylate, wherein the content of recycled methyl methacrylate is 0.5 to 99.5% by mass, and the content of non-recycled methyl methacrylate is 0.5 to 99.5% by mass.

[0037] According to the methyl methacrylate composition of the present embodiment, the heat resistance of the methyl methacrylate polymer obtained by polymerizing the methyl methacrylate composition and the molded product thereof, specifically, the 5% weight loss temperature (temperature at 5% weight loss) and the glass transition temperature can be improved, and the 5% weight loss temperature and the glass transition temperature can be balanced to achieve a good balance. In addition, the methyl methacrylate composition can maintain high quality (for example, yellowing is suppressed) even after long-term storage, and can show good storage properties. Therefore, after the composition is prepared, it can maintain high quality even if it is stored for a long time, and can be used in the manufacture of molded products, etc. as appropriate.

[0038] The methyl methacrylate composition of the present embodiment is generally in a liquid state, but is not limited thereto. Components that can be contained in the methyl methacrylate composition of the present embodiment will be specifically described below.

[0039] (1) Methyl methacrylate

[0040] In the present embodiment, "methyl methacrylate" refers to methyl methacrylate that does not substantially contain impurities such as byproducts such as methyl isobutyrate. However, the present invention is not limited thereto without prejudice to the purpose of the present invention. In other words, "methyl methacrylate" may contain impurities that cannot be completely removed by a purification method according to a conventional method, or may contain impurities in a content that cannot be detected by a detection method according to a conventional method.

[0041] In the present embodiment, the method for producing methyl methacrylate is not particularly limited. Examples of the method for producing methyl methacrylate as a raw material of the methyl methacrylate composition of the present embodiment include the "ACH (acetone cyanohydrin) method" using acetone and hydrogen cyanide (cyanic acid) as raw materials, the "C4 direct oxidation method" using isobutylene or tert-butyl alcohol as raw materials, and the "Alpha method" using ethylene as a raw material.

[0042] As the raw material of the methyl methacrylate composition of the present embodiment, a product containing components other than methyl methacrylate such as methyl isobutyrate, methyl isobutyrate, and / or methyl acrylate in an amount that may be inevitably mixed by the above-mentioned production method (sometimes referred to as a methyl methacrylate product) can be used.

[0043] The methyl methacrylate (or methyl methacrylate product) that can be used as the raw material of the methyl methacrylate composition of the present embodiment and produced by the above-mentioned production method may be purified by any suitable purification method known in the art.

[0044] The content of methyl isobutyrate that may be contained in the methyl methacrylate product as a raw material of the methyl methacrylate composition of the present embodiment is preferably more than 0 mass ppm and 300 mass ppm or less when the total amount of the methyl methacrylate product is 100 parts by mass, and / or the content of methyl acrylate that may be contained in the methyl methacrylate product is preferably 0 mass ppm to 20000 mass ppm.

[0045] In the methyl methacrylate composition of the present embodiment, the content of methyl methacrylate is usually 85% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, further preferably 98% by mass or more, and particularly preferably 99% by mass or more, when the total amount of the methyl methacrylate composition is 100% by mass, from the viewpoint of achieving good heat resistance.

[0046] In the present embodiment, the methyl methacrylate composition contains regenerated methyl methacrylate and non-regenerated methyl methacrylate as methyl methacrylate. Hereinafter, regenerated methyl methacrylate and non-regenerated methyl methacrylate will be described.

[0047] (1-1) Regeneration of methyl methacrylate

[0048] In the present embodiment, "regenerated methyl methacrylate" refers to methyl methacrylate derived from chemical recycling, obtained by regenerating polymethyl methacrylate by depolymerization (chemical recycling), that is, by molding methyl methacrylate and a methyl methacrylate composition containing methyl methacrylate as a main component into various shapes by any suitable injection molding process known in the past. Specifically, "regenerated methyl methacrylate" refers to methyl methacrylate (regenerated MMA) recovered by, for example, heating polymethyl methacrylate obtained by polymerizing methyl methacrylate under any suitable conditions known in the past, more specifically, for example, recovered after being circulated in the market and applied to various purposes, or before being circulated in the market (for example, the overproduction portion) molded body containing polymethyl methacrylate as a main component to decompose (depolymerize) it by heat treatment.

[0049] In the present embodiment, the embodiment of chemical recycling for obtaining regenerated methyl methacrylate is not particularly limited. In the present embodiment, chemical recycling can be implemented using any suitable device known in the past under any suitable conditions (thermal decomposition conditions) known in the past. For example, the thermal decomposition temperature can be set to, for example, about 300 to 600°C, preferably about 350 to 500°C, and more preferably about 400 to 500°C. When the thermal decomposition is performed using an extruder, when it is within the above range, the regenerated methyl methacrylate that can be used in the composition of the present embodiment can be obtained.

[0050] By depolymerizing polymethyl methacrylate (e.g., chemical recycling), a regenerated methyl methacrylate product generally containing regenerated methyl methacrylate can be obtained. Components other than regenerated methyl methacrylate contained in the regenerated methyl methacrylate product include, for example, methyl isobutyrate, methyl propionate, methyl acrylate, and other components derived from the depolymerization of polymethyl methacrylate, i.e., chemical recycling.

[0051] According to chemical recycling, methyl methacrylate can be recovered and regenerated at a high yield. In addition, by implementing any suitable further purification process known in the past after depolymerization, the content (concentration) of low-boiling point compounds (impurities) as by-products such as methyl propionate, methyl isobutyrate and methyl acrylate that may inevitably be contained in the generated regenerated methyl methacrylate product containing methyl methacrylate as the main component can be effectively reduced. The purification process can be carried out at a temperature that can reduce impurities, for example, as long as it is carried out in the range of 30 to 130°C, preferably 30 to 120°C. In addition, the purification process can be carried out under reduced pressure conditions as long as the regenerated methyl methacrylate can be recovered. When the purification process is carried out under a reduced pressure environment, it can be carried out at less than 100°C, preferably in the range of 30 to 80°C, and more preferably 50 to 80°C.

[0052] The regenerated methyl methacrylate product contains regenerated methyl methacrylate usually at 80% by mass or more, preferably at 85% by mass or more, more preferably at 90% by mass or more, further preferably at 92% by mass or more, and still further preferably at 95% by mass or more. The upper limit of the content of regenerated methyl methacrylate is not particularly limited, and may be 100% by mass, or may be 99% by mass or less, or 98% by mass or less. That is, the regenerated methyl methacrylate product usually contains regenerated methyl methacrylate in the range of 80 to 100% by mass, and preferably contains regenerated methyl methacrylate in the range of 85 to 99% by mass.

[0053] Although regenerated methyl methacrylate is basically methyl methacrylate having the same chemical structure as non-regenerated methyl methacrylate, it has been found that if regenerated methyl methacrylate is added to non-regenerated methyl methacrylate, the physical properties of the composition or polymer will change. The reason is still uncertain, but it is speculated that it is because the regenerated methyl methacrylate undergoes thermal decomposition (depolymerization) during the production process, and for some reason, the reactivity changes from non-regenerated methyl methacrylate to become another component that behaves differently from non-regenerated methyl methacrylate. As such reasons, the disappearance of at least part of the reaction points, changes in purity, changes in the interaction between monomers, etc. can be considered.

[0054] (1-2) Non-regenerated methyl methacrylate

[0055] In the present embodiment, "non-regenerated methyl methacrylate" refers to methyl methacrylate that does not belong to the "regenerated methyl methacrylate" already described, and specifically, for example, refers to methyl methacrylate that is not polymerized after being produced by a predetermined production method and is not used for various purposes (virgin methyl methacrylate).

[0056] As already explained, non-regenerated methyl methacrylate may inevitably contain other components (impurities) such as methyl isobutyrate, methyl propionate, and methyl acrylate. A composition containing such non-regenerated methyl methacrylate and other components is sometimes referred to as a non-regenerated methyl methacrylate product. The non-regenerated methyl methacrylate content of the non-regenerated methyl methacrylate product is generally 95% by mass or more, preferably 96% by mass or more, more preferably 97% by mass or more, further preferably 98% by mass or more, and further preferably 99% by mass or more. The upper limit is not particularly limited and may be 100% by mass. That is, the non-regenerated methyl methacrylate content of the non-regenerated methyl methacrylate product is generally in the range of 95 to 100% by mass, preferably in the range of 96 to 99% by mass.

[0057] In the present embodiment, the method for producing non-regenerated methyl methacrylate that can be used as a raw material for the methyl methacrylate composition is not particularly limited. Examples of the method for producing non-regenerated methyl methacrylate that is a raw material for the methyl methacrylate composition of the present embodiment include the "ACH (acetone cyanohydrin) method", "C4 direct oxidation method" and "Alpha method" that have been described. In the present embodiment, non-regenerated methyl methacrylate can be produced by any of them.

[0058] In the methyl methacrylate composition of the present embodiment, the non-regenerated methyl methacrylate includes methyl methacrylate produced using plant-derived raw materials (sometimes referred to as bio-MMA). Specifically, bio-MMA can include methyl methacrylate produced by the ACH (acetone cyanohydrin) method, C4 direct oxidation method, Alpha method, etc., which are produced by decomposition, fermentation, etc. of plant-derived substances such as starch and polysaccharides derived from plants such as corn, wheat, and potatoes by microbial decomposition, fermentation, etc., using butanol, isobutylene, ethanol, ethylene, methanol, propylene acetone, etc., as raw materials.

[0059] In the present embodiment, as long as raw materials, reagents, etc. produced by decomposition, fermentation, etc. by microorganisms are used, for example, methyl methacrylate produced by the above-mentioned production method can be included in the "bio-MMA".

[0060] In addition, bio-MMA can contain carbon 12 ( 12 C) radioactive isotope of carbon 14 ( 14 C), on the other hand, methyl methacrylate derived from mineral resources such as petroleum does not contain carbon 14 ( 14 C). Therefore, whether non-regenerated methyl methacrylate, regenerated methyl methacrylate, methyl methacrylate composition, or a molded product obtained by molding the methyl methacrylate composition contains bio-MMA or is derived from bio-MMA can be detected by any suitable method known in the art. 14 C) to confirm.

[0061] The non-regenerated methyl methacrylate produced by the above production method can be subjected to any conventionally known appropriate purification step to effectively reduce the content (concentration) of impurities that may be inevitably contained in the produced non-regenerated methyl methacrylate product containing methyl methacrylate as a main component.

[0062] In the methyl methacrylate composition of the present embodiment, from the viewpoint of achieving a good balance between the 5% weight loss temperature and the glass transition temperature and suppressing the occurrence of yellowing, the content of the recycled methyl methacrylate and the non-recycled methyl methacrylate is preferably 0.5 to 99.5% by mass and the content of the non-recycled methyl methacrylate is preferably 0.5 to 99.5% by mass when the total amount of the methyl methacrylate composition is 100% by mass. As for the contents thereof, the content of the recycled methyl methacrylate is more preferably 3 to 90% by mass and the content of the non-recycled methyl methacrylate is 10 to 97% by mass, more preferably the content of the recycled methyl methacrylate is 5 to 80% by mass and the content of the non-recycled methyl methacrylate is 20 to 95% by mass, still more preferably the content of the recycled methyl methacrylate is 10 to 70% by mass and the content of the non-recycled methyl methacrylate is 30 to 90% by mass, and still more preferably the content of the recycled methyl methacrylate is 20 to 60% by mass and the content of the non-recycled methyl methacrylate is 40 to 80% by mass. When the content of the regenerated methyl methacrylate and the non-regenerated methyl methacrylate is within the above range, the heat resistance of the polymer of the methyl methacrylate composition and the molded product thereof can be improved, and the yellowing of the methyl methacrylate composition can be suppressed, and the storage stability can be improved. In addition, in another embodiment, it is more preferred that the content of the regenerated methyl methacrylate is 3 to 40% by mass, and the content of the non-regenerated methyl methacrylate is 60 to 97% by mass, and it is further preferred that the content of the regenerated methyl methacrylate is 3 to 20% by mass, and the content of the non-regenerated methyl methacrylate is 80 to 97% by mass.

[0063] (2) Alkyl acrylate

[0064] The methyl methacrylate composition of the present embodiment may further include an alkyl acrylate. The alkyl acrylate that may be included in the methyl methacrylate composition of the present embodiment may be methyl acrylate generated by the method for producing methyl methacrylate described above and inevitably mixed therein, and methyl acrylate that is inevitably generated by the depolymerization involved in the above-mentioned chemical recycling. In addition, the alkyl acrylate that may be included in the methyl methacrylate composition of the present embodiment may be an alkyl acrylate that is intentionally mixed into the above-mentioned methyl methacrylate product (regenerated methyl methacrylate product, non-regenerated methyl methacrylate product). Examples of such alkyl acrylates include methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate.

[0065] The content of the alkyl acrylate that can be contained in the methyl methacrylate composition of the present embodiment is preferably 0% by mass to 10% by mass, and more preferably 0% by mass to 5% by mass.

[0066] The concentration of methyl acrylate that can be contained in the methyl methacrylate composition of the present embodiment is preferably 5 mass ppm to 50,000 mass ppm, and more preferably 5 mass ppm to 30,000 mass ppm.

[0067] (3) Other low-content ingredients

[0068] The methyl methacrylate composition of the present embodiment may contain other low-content components, in addition to the "impurities" already described, particularly resulting from the recovery process of the regenerated methyl methacrylate. Examples of other low-content components include methanol, methyl 2,4-dimethyl-4-pentenoate, 1-butanol, and butyl acrylate; and methyl 2-methyl-3-butenoate, methyl tiglate, methyl 3-methyl-3-butenoate, methyl 3-methyl-2-butenoate, dimethyl itaconate, dimethyl 2-methyl-5-methylene adipate, toluene, and styrene.

[0069] When the methyl methacrylate composition of the present embodiment further contains one or more selected from the group consisting of methanol, methyl 2,4-dimethyl-4-pentenoate, 1-butanol and butyl acrylate among the above-mentioned other low-content components, the concentration of each of methanol, methyl 2,4-dimethyl-4-pentenoate, 1-butanol and butyl acrylate is preferably 10 to 5000 mass ppm, and more preferably 10 to 4000 mass ppm, when the total amount of the methyl methacrylate composition is 100 parts by mass.

[0070] When the methyl methacrylate composition of the present embodiment further contains one or more selected from the group consisting of methyl 2-methyl-3-butenoate, methyl tiglic acid, methyl 3-methyl-3-butenoate, methyl 3-methyl-2-butenoate, dimethyl itaconate, dimethyl 2-methyl-5-methylene adipate, toluene and styrene among the above-mentioned other low-content components, the concentration of each of methyl 2-methyl-3-butenoate, methyl tiglic acid, methyl 3-methyl-3-butenoate, methyl 3-methyl-2-butenoate, dimethyl itaconate, dimethyl 2-methyl-5-methylene adipate, toluene and styrene is preferably 10 to 1000 parts by mass, and more preferably 10 to 800 parts by mass, based on 100 parts by mass of the total amount of the methyl methacrylate composition.

[0071] According to the methyl methacrylate composition of the present embodiment, even if the above-mentioned other low-content components are further included at the above-mentioned concentration, the methyl methacrylate-based polymer obtained by polymerizing the methyl methacrylate composition and the molded product thereof can have good 5% weight loss temperature and glass transition temperature, and the 5% weight loss temperature and glass transition temperature are balanced to make them well balanced. Specifically, for example, the 5% weight loss temperature and glass transition temperature of the methyl methacrylate composition of the present embodiment can show values ​​much higher than the 5% weight loss temperature and glass transition temperature predicted from non-regenerated methyl methacrylate or regenerated methyl methacrylate alone. For example, when the measured values ​​of the 5% weight loss temperature of the above-mentioned independent molded product and the composition of the present embodiment are plotted in relation to the content of regenerated methyl methacrylate, and the measured values ​​of the independent molded product are connected with a straight line, the methyl methacrylate composition of the present embodiment can show a measured value exceeding the straight line. In addition, the same is true for the glass transition temperature.

[0072] In addition, according to the methyl methacrylate composition of the present embodiment, good storage properties can be exerted, and degradation such as yellowing during storage can be suppressed. Since degradation during storage is observed in non-regenerated methyl methacrylate and regenerated methyl methacrylate, the effect obtained by mixing the two in a specified ratio can be said to be an unexpected and surprising effect. Although the reason is still uncertain, it is believed that by adding regenerated methyl methacrylate to non-regenerated methyl methacrylate, certain effects (for example, interactions between monomers, etc.) different from the case of non-regenerated methyl methacrylate alone or the case of regenerated methyl methacrylate alone are produced.

[0073] (4) Other ingredients

[0074] The methyl methacrylate composition of the present embodiment may contain, in addition to the components described in (1) to (3) above, other components such as a mold release agent, a polymerization regulator, a polymerization initiator, an ultraviolet absorber, and a colorant that can be added to produce a molded body having predetermined properties, provided that the purpose of the present invention is not impaired. Other components that may be contained in the methyl methacrylate composition of the present embodiment will be described below.

[0075] (i) Release agent

[0076] The methyl methacrylate composition of the present embodiment may contain a release agent for improving the releasability of a molded article, particularly when producing a methyl methacrylate polymer obtained by polymerizing the methyl methacrylate composition and a molded article thereof.

[0077] Examples of the release agent that can be contained in the methyl methacrylate composition of the present embodiment include higher fatty acid esters, higher aliphatic alcohols, higher fatty acids, higher fatty acid amides, higher fatty acid metal salts, and fatty acid derivatives.

[0078] Specific examples of the release agent that can be included in the methyl methacrylate composition of the present embodiment include sodium di-(2-ethylhexyl)sulfosuccinate, stearyl alcohol, methyl stearate, and stearic acid amide. In the methyl methacrylate composition of the present embodiment, the above release agents can be used alone or in combination of two or more.

[0079] The content of the release agent in the methyl methacrylate composition of the present embodiment can be, for example, 0.01 to 1.0 parts by mass when the total amount of the methyl methacrylate composition is 100 parts by mass.

[0080] (ii) Polymerization regulator

[0081] The methyl methacrylate composition of the present embodiment may contain a polymerization regulator capable of regulating the polymerization rate in the polymerization reaction of methyl methacrylate.

[0082] As the polymerization modifier that can be contained in the methyl methacrylate composition of the present embodiment, any conventionally known appropriate polymerization modifier can be used. As such a polymerization modifier, for example, a compound that can adjust in a direction to reduce the polymerization rate can be used.

[0083] Specific examples of suitable polymerization regulators include thiol compounds such as n-butyl mercaptan and n-octyl mercaptan, terpenoid compounds such as limonene, myrcene, α-terpinene, β-terpinene, γ-terpinene, terpinolene, β-pinene, and α-pinene, and α-methylstyrene dimer. In this embodiment, terpinolene, which is a terpene compound, is preferably used as the polymerization regulator.

[0084] In the methyl methacrylate composition of the present embodiment, the above-mentioned polymerization regulators may be used alone or in combination of two or more.

[0085] The content of the polymerization regulator in the methyl methacrylate composition of the present embodiment can be, for example, 0.001 to 0.5 parts by mass when the total amount of the methyl methacrylate composition is 100 parts by mass.

[0086] (iii) Polymerization initiator

[0087] Examples of the polymerization initiator that can be contained in the methyl methacrylate composition of the present embodiment include radical polymerization initiators, diacyl peroxide initiators, dialkyl peroxide initiators, peroxyester initiators, percarbonate initiators, and peroxyketal initiators.

[0088] Specific examples of the radical polymerization initiator include azo compounds such as 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4,4-trimethylpentene), 2,2'-azobis(2-methylpropane), 2-cyano-2-propylazocarbonamide, 2,2'-azobis(2-hydroxy-propionic acid methyl ester), 2,2'-azobis(2-methyl-butyronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] and 2,2'-azobis(2-methylpropionic acid) dimethyl ester.

[0089] Specific examples of the diacyl peroxide initiator and the dialkyl peroxide initiator include dicumyl peroxide, tert-butylcumyl peroxide, di-tert-butyl peroxide, benzoyl peroxide, and lauroyl peroxide.

[0090] Specific examples of the peroxyester initiator include tert-butyl peroxy-3,3,5-trimethylhexanoate, tert-butyl peroxylaurate, tert-butyl peroxyisobutyrate, tert-butyl peroxyacetate, di-tert-butyl peroxyhexahydroterephthalate, di-tert-butyl peroxyazelaate, tert-butyl peroxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, and tert-amyl peroxy-2-ethylhexanoate.

[0091] Specific examples of the percarbonate initiator include tert-butyl peroxyallyl carbonate and tert-butyl peroxyisopropyl carbonate.

[0092] Specific examples of the peroxyketal initiator include 1,1-di-tert-butylperoxycyclohexane, 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, and 1,1-di-tert-hexylperoxy-3,3,5-trimethylcyclohexane.

[0093] In the methyl methacrylate composition of the present embodiment, the above-mentioned polymerization initiators may be used alone or in combination of two or more.

[0094] The content of the polymerization initiator in the methyl methacrylate composition of the present embodiment can be, for example, 0.01 to 5 parts by mass when the total amount of the methyl methacrylate composition is 100 parts by mass.

[0095] (iv) UV absorber

[0096] The methyl methacrylate composition of the present embodiment may contain an ultraviolet absorber in order to further improve the weather resistance of the produced polymethyl methacrylate and its molded article.

[0097] Examples of suitable ultraviolet absorbers that can be contained in the methyl methacrylate composition of the present embodiment include benzophenone ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, benzotriazole ultraviolet absorbers, malonate ultraviolet absorbers, and oxalic acid anilide ultraviolet absorbers.

[0098] Specific examples of the ultraviolet absorber include 2(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-hydroxy-4-n-octylbenzophenone, 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, and 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate.

[0099] In the methyl methacrylate composition of the present embodiment, the above-mentioned ultraviolet absorbers may be used alone or in combination of two or more.

[0100] The content of the ultraviolet absorber in the methyl methacrylate composition of the present embodiment can be, for example, 0.001 to 1 part by mass when the total amount of the methyl methacrylate composition is 100 parts by mass.

[0101] (v) Colorants

[0102] The methyl methacrylate composition of the present embodiment may contain a colorant for giving the produced methyl methacrylate polymer and a molded article thereof any appropriate color.

[0103] Examples of suitable colorants that can be included in the methyl methacrylate composition of the present embodiment include perylene dyes, perinone dyes, pyrazolone dyes, methine dyes, coumarin dyes, quinophthalone dyes, quinoline dyes, anthraquinone dyes (e.g., Sumiplast Violet B), anthraquinone dyes, anthrapyridone dyes, thioindigo dyes, coumarin dyes, isoindolinone pigments, diketopyrrolopyrrole pigments, condensed azo pigments, benzimidazolone pigments, dioxazine pigments, copper phthalocyanine pigments, and quinacridone pigments.

[0104] The above colorants may be used alone or in combination of two or more.

[0105] The content of the colorant in the methyl methacrylate composition of the present embodiment can be, for example, 1.0×10 -8 Mass parts to 0.5 mass parts.

[0106] 2. Method for producing methyl methacrylate composition

[0107] The methyl methacrylate composition of the present embodiment can be produced by mixing the components described above under any appropriate conditions by any appropriate conventionally known method.

[0108] Specifically, the methyl methacrylate composition of the present embodiment can be produced by preparing the components described above in predetermined amounts and mixing them in a mixing tank that can be controlled to a constant temperature using a heat medium jacket having any conventionally known suitable structure.

[0109] The methyl methacrylate composition of the present embodiment may be obtained by purifying the methyl methacrylate composition (mixture) produced by the above-mentioned production method by any conventionally known appropriate purification method.

[0110] As described above, according to the method for producing a methyl methacrylate composition of the present embodiment, a methyl methacrylate composition capable of producing a methyl methacrylate polymer having excellent properties as described above, and a molded article thereof can be produced simply and at low cost.

[0111] 3. Method for producing methyl methacrylate polymer and molded article

[0112] In the present embodiment, the method for producing a methyl methacrylate polymer includes a step of polymerizing a methyl methacrylate composition. The method for producing a methyl methacrylate polymer from the methyl methacrylate composition of the present embodiment is not particularly limited. Specifically, the methyl methacrylate polymer produced by polymerizing the methyl methacrylate composition can be produced by any suitable method selected in consideration of the components and contents thereof contained in the methyl methacrylate composition of the present embodiment.

[0113] In the present embodiment, examples of the method for polymerizing the methyl methacrylate composition include bulk polymerization (bulk polymerization), solution polymerization, suspension polymerization, and emulsion polymerization.

[0114] Specifically, for example, by polymerizing the methyl methacrylate composition of the present embodiment by a bulk polymerization method, a molded body of a methyl methacrylate-based polymer, that is, a molded body containing polymethyl methacrylate can be obtained. In addition, in a slot die casting polymerization (cell-cast), by subjecting the methyl methacrylate composition to any appropriate heating treatment under predetermined heating conditions to allow the polymerization reaction to proceed, a molded body of a methyl methacrylate-based polymer obtained by polymerizing and curing the methyl methacrylate contained in the methyl methacrylate composition can be obtained.

[0115] In the method for polymerizing the methyl methacrylate composition (methyl methacrylate) of the present embodiment to produce a methyl methacrylate-based polymer, and the method for producing a molded article obtained by polymerizing and molding the methyl methacrylate composition, the heating temperature and heating time among the heating conditions can be appropriately set in consideration of, for example, the type or content of the selected polymerization regulator, polymerization initiator and / or other components, the content of methyl methacrylate, and the concentration of other components that may be included, such as alkyl acrylate.

[0116] In the present embodiment, when producing a molded product of a methyl methacrylate polymer in slot die casting polymerization, the heating temperature can be, for example, 50° C. to 130° C., and the heating time can be, for example, 1 hour to 20 hours.

[0117] The heat treatment in the method for producing a polymer and a molded article according to the present embodiment can be a heat treatment including a plurality of steps with different heating temperatures and / or heating times.

[0118] The polymer and its molded article according to the present embodiment can be produced by, for example, performing a heat treatment under heating conditions including the following steps 1 to 7.

[0119] Step 1: Raise the temperature from room temperature to 68°C in 20 minutes.

[0120] Step 2: Keep at 68°C for 90 minutes.

[0121] Step 3: Cool down from 68°C to 64°C in 20 minutes.

[0122] Step 4: Keep at 64°C for 90 minutes.

[0123] Step 5: Raise the temperature from 64°C to 123°C over 10 minutes.

[0124] Step 6: Maintain at 123°C for 120 minutes.

[0125] Step 7: Cool down from 123°C to room temperature in 90 minutes.

[0126] In the method for producing a methyl methacrylate-based polymer and a molded article according to the present embodiment, by carrying out the above-mentioned steps 1 to 7 in this order, it is possible to suppress heat generation during the polymerization reaction and stably complete the polymerization reaction.

[0127] When the methyl methacrylate composition of the present embodiment is subjected to heat treatment, a molded body of a predetermined shape can be formed by, for example, applying a slot die casting method (slot die casting polymerization) using a slot die that can define a closed space of a predetermined shape inside. The method for producing a molded body by the slot die casting method is specifically described below.

[0128] When a molded body of a methyl methacrylate polymer is produced by slot die casting, a slot die is first prepared. Here, an example of forming a molded body as a plate-like body (sometimes also referred to as a cast plate) is described.

[0129] Such a slot die can be composed of at least two flat plate members and a seal (gasket) which is arranged to be sandwiched by the two flat plate members and can seal the gap between the two flat plate members arranged to face each other into a closed space.

[0130] The flat plate-shaped member may be a single piece or a strip. The flat plate-shaped member may be made of a material that is not dissolved by the methyl methacrylate composition of the present embodiment, does not hinder polymerization, and has sufficient heat resistance to the heating temperature in the heat treatment. Examples of suitable materials for the flat plate-shaped member include glass and metal.

[0131] As the seal, any suitable seal known in the art can be used. The seal can be made of a material that is not dissolved by the methyl methacrylate composition of the present embodiment, does not hinder the polymerization reaction, and has sufficient heat resistance to the heating temperature in the heat treatment. As a suitable specific example of the seal, a vinyl chloride resin gasket can be cited.

[0132] Next, the methyl methacrylate composition of the present embodiment is injected into the gap (space) defined by the slot die prepared as described above by any conventionally known appropriate method.

[0133] Next, the slot mold is subjected to a heat treatment under the heating conditions described above. The method for heat treatment of the slot mold into which the methyl methacrylate composition of the present embodiment is injected is not particularly limited. The method for heat treatment of the slot mold is similar to the conventionally known slot mold casting method, and can be, for example, the following methods: a method of directly performing a heat treatment from the outside of the slot mold using a hot air circulation furnace, an infrared heater, etc.; and a method of further providing any suitable conventionally known jacket on the outside of the slot mold and introducing a heat medium such as warm air, warm water, or steam into the jacket.

[0134] 4. Determination of 5% weight loss temperature (heating weight loss rate) of molded body

[0135] In the present embodiment, the 5% weight loss temperature of the molded article of the methyl methacrylate polymer can be measured using a conventionally known thermogravimetric / differential thermal analyzer (for example, "TG / DTA7200" manufactured by Hitachi High-Tech Sciences, Ltd.).

[0136] Specifically, a test piece which is a pulverized product obtained by pulverizing a molded body such as a cast plate into a state where the diameter or the length of each side becomes 0.5 mm or less is used, and a heat treatment is performed at a specified gas flow rate and a heating rate to a specified temperature under the flow of an inert gas using a thermogravimetric / differential thermal analysis apparatus, and the weight of the test piece after the heat treatment is measured, thereby being able to calculate the 5% weight loss temperature based on the measured weight and the initial weight.

[0137] In the present embodiment, the 5% weight loss temperature of the molded product, that is, the methyl methacrylate polymer, is preferably 260°C to 360°C, and more preferably 290°C to 330°C.

[0138] When the 5% weight loss temperature of the methyl methacrylate polymer is lower than 260°C, the molded article obtained using the methyl methacrylate polymer may have a poor appearance. On the other hand, when the 5% weight loss temperature of the methyl methacrylate polymer exceeds 330°C, the thermal decomposition of the molded article obtained using the methyl methacrylate polymer may require a large amount of energy.

[0139] Regarding the recycled methyl methacrylate product as a raw material of the composition, the 5% weight reduction temperature of the molded body obtained by using its homopolymer (recycled methyl methacrylate polymer) is usually 300°C or higher, preferably 310°C or higher, and more preferably 320°C or higher. The upper limit is usually 400°C or lower, preferably 380°C or lower, and more preferably 350°C or lower. Regarding the non-recycled methyl methacrylate product as a raw material, the 5% weight reduction temperature of the molded body obtained by using its homopolymer (non-recycled methyl methacrylate polymer) is usually 200°C or higher, preferably 250°C or higher. The upper limit is usually less than 300°C, preferably 290°C or lower. It is preferred that the 5% weight reduction temperature of the molded body of the recycled methyl methacrylate polymer is higher than that of the molded body of the non-recycled methyl methacrylate polymer, and the difference is usually 10°C or higher, preferably 20°C or higher, and more preferably 30°C or higher. The upper limit is usually 50°C or lower, preferably 40°C or lower.

[0140] 5. Determination of glass transition temperature

[0141] In the present embodiment, the glass transition temperature of the molded article of the methyl methacrylate polymer is the glass transition temperature (Tmg) (° C.) measured in accordance with JIS-K7121.

[0142] The glass transition temperature can be measured using any conventionally known appropriate measuring device (for example, “DSC7020” manufactured by Hitachi High-Tech Sciences, Ltd., which is a differential scanning calorimeter).

[0143] Specifically, a test piece obtained by crushing a molded body such as a cast plate into a diameter or each side length of 0.5 mm or less can be used, and the test piece is completely melted in an inert gas atmosphere, and then the measurement is performed based on a DSC curve obtained from a predetermined temperature profile.

[0144] In the present embodiment, the glass transition temperature of the methyl methacrylate polymer as the molded product is usually 100°C to 130°C or 105°C to 125°C, preferably 110°C to 120°C, and more preferably 110°C to 115°C.

[0145] The glass transition temperature of the polymer (molded product) of regenerated methyl methacrylate is usually 90°C or more, preferably 95°C or more, more preferably 100°C or more, and further preferably 105°C or more. The upper limit is usually 130°C or less, preferably 120°C or less, and more preferably 110°C or less. The glass transition temperature of the polymer (molded product) of non-regenerated methyl methacrylate is usually 105°C or more, and preferably 110°C or more. The upper limit is usually 150°C or less, and preferably 140°C or less. It is preferred that the glass transition temperature of the regenerated methyl methacrylate polymer (molded product) is lower than the glass transition temperature of the non-regenerated methyl methacrylate polymer (molded product), and the difference is usually 2°C or more, preferably 2.5°C or more, and more preferably 3°C or more. The upper limit is usually 10°C or less, preferably 9°C or less, and more preferably 8°C or less.

[0146] 6. Determination of yellowing degree

[0147] The yellowing degree (YI value) of the molded body of the methyl methacrylate-based polymer in the present embodiment can be calculated according to the method described in JIS K7373. In the examples described later, the composition to be measured is placed in a quartz glass tank of 10 mm in length × 10 mm in width × 45 mm in height, and the yellowing degree (YI value) when the optical path length is set to 10 mm is calculated according to the method described in JIS K7373. In the measurement, a commercially available spectrophotometer can be used, for example, as long as it is carried out under the following conditions. The smaller the calculated YI value, the more the yellowing is suppressed. For example, the YI value measured under the measurement conditions of the embodiment is preferably less than 0.1.

[0148] (YI measurement conditions)

[0149] Light source: C light source

[0150] Field of view: 2 degrees

[0151] Calculation formula: YI = (1.2769 × X - 1.0592 × Z) / Y × 100

[0152] 7. Use of polymers and their shaped bodies

[0153] The polymer of the methyl methacrylate composition of this embodiment and its molded article have excellent light transmittance, heat resistance, and weather resistance. Therefore, they can be suitably used in various applications such as lighting fixtures, automobile parts, signs, and building materials that may be exposed to the external environment and may also be exposed to heat sources and light sources.

[0154] Example

[0155] Examples according to the embodiments of the present invention will be described. However, the present invention is not limited to the examples described below.

[0156] <Preparation Example 1>

[0157] Preparation of regenerated methyl methacrylate product (recovered MMA)

[0158] A polymethyl methacrylate resin (SUMIPEX MH, manufactured by Sumitomo Chemical Co., Ltd.) was thermally decomposed (depolymerized) using a twin-screw extruder (TEX-44, manufactured by The Japan Steel Works, Ltd.) under the following thermal decomposition conditions.

[0159] The methyl methacrylate product containing methyl methacrylate obtained by thermal decomposition was condensed using a heat exchanger to obtain a crude regenerated methyl methacrylate product.

[0160] Next, the crude regenerated methyl methacrylate product was purified using a rotary evaporator (R-300, manufactured by BUCHI) under the following purification conditions to obtain a regenerated methyl methacrylate product.

[0161] The content of regenerated methyl methacrylate contained in the obtained regenerated methyl methacrylate product was 97.3% by mass.

[0162] (Thermal decomposition conditions)

[0163] Barrel temperature: 450℃

[0164] Speed: 500rpm

[0165] Screw L / D: 60

[0166] Resin supply: 40kg / hr

[0167] (Purification conditions)

[0168] Bath temperature: 50℃

[0169] Circulating water temperature: 5℃

[0170] Pressure: above 90mbar

[0171] <Preparation Example 2>

[0172] Preparation of non-regenerated methyl methacrylate

[0173] Methacrylic acid and methanol are subjected to an esterification reaction in the reactor to obtain methyl methacrylate.

[0174] Unreacted methanol was removed from the obtained methyl methacrylate product containing methyl methacrylate using an extraction column, and then purified using multiple distillation columns according to a conventional method to obtain a non-regenerated methyl methacrylate product. The non-regenerated methyl methacrylate product contained 99.99% by mass of non-regenerated methyl methacrylate.

[0175] <Example 1>

[0176] Preparation of Composition 1

[0177] 5 parts by mass of the regenerated methyl methacrylate product obtained in the above Preparation Example 1 and 95 parts by mass of the non-regenerated methyl methacrylate product obtained in the above Preparation Example 2 were mixed to obtain a methyl methacrylate composition (hereinafter referred to as the composition) 1. The obtained composition 1 was in a liquid state.

[0178] Preparation of Composition 1'

[0179] Composition 1 (99.83 parts by mass), sodium di-(2-ethylhexyl)sulfosuccinate (0.05 parts by mass) as a mold release agent, terpinolene (0.01 parts by mass) as a polymerization regulator, 2,2'-azobisisobutyronitrile (0.08 parts by mass) as a polymerization initiator, and 2(2'-hydroxy-5'-methylphenyl)benzotriazole (0.01 parts by mass) as an ultraviolet absorber were mixed to obtain a composition 1' for forming a molded body (casting plate). The obtained composition 1' was in a liquid state.

[0180] ·Manufacturing of casting plate 1

[0181] A slot mold was prepared in which a 3.8 mm thick vinyl chloride resin gasket was sandwiched between two glass plates facing each other, and a closed gap was defined by the vinyl chloride resin gasket and the two glass plates.

[0182] The composition 1' was injected into the gap in the slot mold. The slot mold injected with the composition 1' was placed in an oven, and the composition 1' was polymerized by heating under heating conditions including the following steps 1 to 7 in order, thereby producing a casting plate 1 of a molded body of methyl methacrylate-based polymer having a thickness of 3 mm and a square size of 250 mm.

[0183] (Heating conditions)

[0184] Step 1: Raise the temperature from room temperature to 68°C in 20 minutes.

[0185] Step 2: Keep at 68°C for 90 minutes.

[0186] Step 3: Cool down from 68°C to 64°C in 20 minutes.

[0187] Step 4: Keep at 64°C for 90 minutes.

[0188] Step 5: Raise the temperature from 64°C to 123°C over 10 minutes.

[0189] Step 6: Maintain at 123°C for 120 minutes.

[0190] Step 7: Cool down from 123°C to room temperature in 90 minutes.

[0191] ·Determination of 5% weight loss temperature of cast plate 1

[0192] 9.3 mg of the pulverized product obtained by pulverizing the cast plate 1 to a diameter or the length of each side of 0.5 mm or less was placed on an aluminum pan ("P / N SSC000E030 Open Sample Pan" manufactured by Hitachi High-Tech Science Co., Ltd., diameter 5 mm), and then the weight change was measured while heating from 45°C to 520°C under the conditions of setting the nitrogen flow rate to 200 mL / min and the heating rate to 10°C / min. The result was that the weight of the pulverized product decreased as the temperature rose. The weight of the pulverized product at the starting temperature of 45°C was set to 100% by weight, and the temperature (5% weight loss temperature) at which the weight of the pulverized product decreased to 95% by weight was obtained. The results are shown in Table 1.

[0193] ·Determination of glass transition temperature (Tmg) of cast plate 1

[0194] The glass transition temperature (° C.) was measured in accordance with JIS-K7121 using a test piece obtained by pulverizing a cast plate 1 as a molded body of a methyl methacrylate polymer to a diameter or a length of each side of 0.5 mm or less.

[0195] As a measuring device for measuring the glass transition temperature, specifically, a differential scanning calorimeter ("DSC7020" manufactured by Hitachi High-Tech Science Co., Ltd.) was used, and the nitrogen flow rate was set to 50 mL / min. The temperature was raised from room temperature (23°C) to 150°C (1st temperature rise) at 20°C / min, and after being kept at 150°C for 5 minutes to completely melt the test piece, the temperature was lowered from 150°C to -35°C at 10°C / min, and kept at -35°C for 1 minute, and then the temperature was raised again to 210°C at 10°C / min (2nd temperature rise).

[0196] The intersection of the step-shaped change curve at the second temperature rise in the DSC curve obtained from the above temperature distribution diagram and the straight line at an equal distance from the two baseline extension lines in the vertical axis direction (midpoint glass transition temperature) is set as the glass transition temperature (°C). Three points were measured for each test piece, and the average value was calculated and set as the glass transition temperature. The results are shown in Table 1.

[0197] <Example 2>

[0198] Preparation of Composition 2

[0199] 10 parts by mass of the regenerated methyl methacrylate product obtained in the above Preparation Example 1 and 90 parts by mass of the non-regenerated methyl methacrylate product obtained in the above Preparation Example 2 were mixed to obtain Composition 2. The obtained Composition 2 was in a liquid state.

[0200] Composition 2' was prepared in the same manner as in Example 1 except that Composition 2 was used. Then, a cast plate 2 was produced, and the 5% weight loss temperature and the glass transition temperature were measured. The results are shown in Table 1.

[0201] <Example 3>

[0202] Preparation of Composition 3

[0203] 30 parts by mass of the regenerated methyl methacrylate product obtained in the above Preparation Example 1 and 70 parts by mass of the non-regenerated methyl methacrylate product obtained in the above Preparation Example 2 were mixed to obtain Composition 3. The obtained Composition 3 was in a liquid state.

[0204] Composition 3' was prepared in the same manner as in Example 1 except that Composition 3 was used. Then, a cast plate 3 was produced, and the 5% weight loss temperature and the glass transition temperature were measured.

[0205] <Example 4>

[0206] Preparation of Composition 4

[0207] 50 parts by mass of the regenerated methyl methacrylate product obtained in the above Preparation Example 1 and 50 parts by mass of the non-regenerated methyl methacrylate product obtained in the above Preparation Example 2 were mixed to obtain Composition 4. The obtained Composition 4 was in a liquid state.

[0208] Composition 4' was prepared in the same manner as in Example 1 except that Composition 4 was used. Then, a cast plate 4 was produced, and the 5% weight loss temperature and the glass transition temperature were measured. The results are shown in Table 1.

[0209] <Example 5>

[0210] Preparation of Composition 5

[0211] 80 parts by mass of the regenerated methyl methacrylate product obtained in the above Preparation Example 1 and 20 parts by mass of the non-regenerated methyl methacrylate product obtained in the above Preparation Example 2 were mixed to obtain Composition 5. The obtained Composition 5 was in a liquid state.

[0212] Composition 5' was prepared in the same manner as in Example 1 except that Composition 5 was used. Then, a cast plate 5 was produced, and the 5% weight loss temperature and the glass transition temperature were measured.

[0213] <Comparative Example 1>

[0214] Preparation of composition C1

[0215] A liquid consisting only of the regenerated methyl methacrylate product obtained in the above-mentioned Preparation Example 1 was designated as Composition C1.

[0216] Composition C1′ was prepared in the same manner as in Example 1 except that composition C1 was used. Then, cast plate C1 was produced, and the 5% weight loss temperature and glass transition temperature were measured.

[0217] <Reference Example 1>

[0218] Preparation of composition R1

[0219] A liquid consisting only of the non-regenerated methyl methacrylate product obtained in the above-mentioned Preparation Example 2 was designated as Composition R1.

[0220] Composition R1′ was prepared in the same manner as in Example 1 except that composition R1 was used. Then, cast plate R1 was produced, and the 5% weight loss temperature and glass transition temperature were measured.

[0221] [Table 1]

[0222] (Table 1)

[0223]

[0224] As is clear from Table 1 above, the molded articles of the methyl methacrylate polymers according to Examples 1 to 5 that satisfy the requirements of the present invention can achieve excellent heat resistance.

[0225] Here, refer to Figure 1-2 The relationship between the ratio of regenerated methyl methacrylate and the 5% weight loss temperature or the glass transition temperature will be described.

[0226] Figure 1 is a graph showing the relationship between the ratio of regenerated methyl methacrylate and the 5% weight loss temperature, Figure 2 The graphs show the relationship between the ratio of recycled methyl methacrylate and the glass transition temperature. The straight line (dashed line) in each graph is a straight line connecting the values ​​of the case where the ratio of recycled MMA is 0% (reference example 1) and the case where the ratio of recycled MMA is 100% (reference example 2).

[0227] like Figure 1 As shown, the methyl methacrylate polymer molded articles according to Examples 1 to 5 satisfying the requirements of the present invention exhibited a good 5% weight loss temperature even when the methyl methacrylate composition contained regenerated methyl methacrylate (regenerated methyl methacrylate product).

[0228] In addition, if Figure 2 As shown, the molded articles of the methyl methacrylate polymers according to Examples 1 to 5 satisfying the requirements of the present invention can achieve excellent glass transition temperatures.

[0229] Depend on Figure 1 and Figure 2 It is clear that the molded articles of the methyl methacrylate polymer according to Examples 1 to 5 satisfying the requirements of the present invention can achieve both the 5% weight loss temperature and the glass transition temperature with a good balance therebetween.

[0230] Regarding the 5% weight loss temperature, one skilled in the art would predict that it would be expressed as a straight line ( Figure 1 The broken line ( ) connects the values ​​of the case where the ratio of recycled methyl methacrylate is 0% (reference example 1) and the case where the ratio of recycled methyl methacrylate is 100% (comparative example 1), but the measured values ​​of Examples 1 to 5 all exceed this prediction, and the maximum increase can reach more than 10°C. In addition, the glass transition temperature is also a predicted value calculated by the formula of FOX, and it is predicted that it will be expressed by a straight line ( Figure 2 The dashed line (shown in Figure 1) connects the values ​​of the case where the ratio of recycled methyl methacrylate is 0% (reference example 1) and the case where the ratio of recycled methyl methacrylate is 100% (comparative example 1), but the measured values ​​of Examples 1 to 5 all clearly exceed this prediction. Specifically, there is a tendency that, except for the case where the ratio of recycled methyl methacrylate is 0% and the case where the ratio of recycled methyl methacrylate is 100%, in the composition containing non-recycled methyl methacrylate and recycled methyl methacrylate, measured values ​​exceeding the straight line can be obtained. This trend is due to the tendency that measured values ​​significantly exceeding the straight line can be obtained in the composition where the ratio of recycled MMA is 5 to 80%.

[0231] <Examples 6 to 7 and Comparative Example 2>

[0232] A regenerated methyl methacrylate product (regenerated MMA (A), content of regenerated methyl methacrylate: 96.7 mass %) was prepared under the same conditions as in Preparation Example 1, except that the bath temperature during purification was changed to 60°C and the pressure was changed to 170 mbar or more (Comparative Example 2). Regenerated MMA (A) and non-regenerated MMA obtained in Preparation Example 2 were mixed in the mixing ratios described in Table 2 to obtain each composition (liquid) (Examples 6 to 7). Under the above conditions, the 5% weight reduction temperature (hereinafter referred to as T5) and the glass transition temperature (hereinafter referred to as Tmg) of the molded body obtained by molding each composition by the above method were measured (Table 2).

[0233] [Table 2]

[0234] (Table 2)

[0235]

[0236] <Examples 8 to 10 and Comparative Example 3>

[0237] A regenerated methyl methacrylate product (regenerated MMA (B): the content of regenerated methyl methacrylate is 97.9% by mass) was prepared under the same conditions as in Preparation Example 1, except that the raw material polymethyl methacrylate resin was changed to PMMA waste (lighting cover) (Comparative Example 3). Regenerated MMA (B) and the non-regenerated methyl methacrylate product (non-regenerated MMA) obtained in Preparation Example 2 were mixed in the mixing ratios described in Table 3 to obtain each composition (liquid) (Examples 8 to 10). Under the above conditions, T5 and Tmg of the molded bodies obtained by molding each composition by the above method were measured (Table 3).

[0238] [Table 3]

[0239] (Table 3)

[0240]

[0241] <Test Examples 11 and 12 and Comparative Example 4>

[0242] A regenerated methyl methacrylate product (regenerated MMA (C), a regenerated methyl methacrylate content of 97.8 mass %) was prepared under the same conditions as in Preparation Example 1 except that the cylinder temperature during thermal decomposition was changed to 400°C (Comparative Example 4). Regenerated MMA (C) and the non-regenerated methyl methacrylate product (non-regenerated MMA) obtained in Preparation Example 2 were mixed at the mixing ratios described in Table 4 to obtain each composition (liquid) (Examples 11 to 12). Under the above conditions, T5 and Tmg of the molded bodies obtained by molding each composition by the above method were measured (Table 4).

[0243] [Table 4]

[0244] (Table 4)

[0245]

[0246] <Example 13 and Comparative Example 5>

[0247] A regenerated methyl methacrylate product (regenerated MMA (D), a regenerated methyl methacrylate content of 97.3 mass %) was prepared under the same conditions as in Preparation Example 1 except that the cylinder temperature during thermal decomposition was changed to 480°C (Comparative Example 5). Regenerated MMA (D) and the non-regenerated methyl methacrylate product (non-regenerated MMA) obtained in Preparation Example 2 were mixed at the mixing ratios described in Table 4 to obtain each composition (liquid) (Example 13). Under the above conditions, T5 and Tmg of the molded bodies obtained by molding each composition by the above method were measured (Table 5).

[0248] [Table 5]

[0249] (Table 5)

[0250]

[0251] The results of T5 and Tg of each test example are plotted on Figure 3 , 4 The results are as follows: the T5 and Tg of the PMMA molded body mixed with the recycled MMA of Examples 1 to 5 of the present application (● in the figure) and the PMMA molded body mixed with the recycled MMA (A) to (D) (□, △, *, ― in the figure, respectively) are higher than the straight line (dashed line) formed by connecting the T5 and Tmg of the molded body of Reference Example 1 (non-recycled MMA 100%) and the T5 of Comparative Example 2 and the Tmg of Comparative Example 5 (the highest value among T5 and Tmg of Comparative Examples 2 to 5). Any one of Tmg and T5 (especially Tmg) has the following tendency: except for the case where the proportion of recycled methyl methacrylate is 0% and the case where the proportion of recycled methyl methacrylate is 100%, in the composition containing non-recycled methyl methacrylate and recycled methyl methacrylate, the measured value exceeding the straight line can be obtained. This tendency is in the tendency that the measured value significantly exceeding the straight line can be obtained in the composition with the proportion of recycled MMA being 5 to 80%.

[0252] (Evaluation of Storage Stability of Composition)

[0253] Compositions 1 to 3 and R1 prepared in Examples 1 to 3, Comparative Example 1 and Reference Example 1 were subjected to storage tests in the order of Steps 1 to 7 described below. The storage test was performed under accelerated conditions (80° C.) to evaluate stability after long-term storage.

[0254] Step 1: 25 mL of the composition was injected into the lower part (container) of a pressure container ("TVS-N2" manufactured by Taisho Glass Industry Co., Ltd.).

[0255] Step 2: Insert a packing between the upper portion (upper cover) and the lower portion of the pressure vessel to seal the pressure vessel.

[0256] Step 3: Nitrogen gas is delivered from the top end (piping) of the pressure vessel, and the internal pressure is sealed at 0.2 MPa, and it is confirmed whether the internal pressure changes within 1 minute.

[0257] Step 4: Install the closing plug on the top of the upper portion of the pressure vessel.

[0258] Step 5: Place the pressure vessel in an oil bath set at 80°C.

[0259] Step 6: Keep in oil bath for 24 hours.

[0260] Step 7: After 24 hours, remove the pressure vessel from the oil bath.

[0261] The composition (4 mL) after the storage test was placed in a quartz glass tank (T-1 manufactured by Daxing Manufacturing Co., Ltd.) with a length of 10 mm × a width of 10 mm × a height of 45 mm. The yellowness (YI value) when the optical path length was set to 10 mm was calculated according to the method described in JIS K7373 (Table 6) using the composition placed in the quartz glass tank. The measurement was performed using a spectrophotometer ("Hitachi Spectrophotometer U-4000" manufactured by Hitachi High-Technologies Corporation) under the following conditions. It can be judged that the smaller the YI value, the more yellow discoloration can be suppressed after storage.

[0262] (YI measurement conditions)

[0263] Light source: C light source

[0264] Field of view: 2 degrees

[0265] Calculation formula: YI = (1.2769 × X - 1.0592 × Z) / Y × 100

[0266] [Table 6]

[0267] (Table 6)

[0268]

[0269] Compared with compositions R1 and C1 of Reference Example 1 and Comparative Example 1, compositions 1 to 3 of Examples 1 to 3 had lower YI values ​​after the storage test, indicating that yellowing after storage was suppressed (Table 6).

Claims

1. A methyl methacrylate composition, characterized in that Contains recycled methyl methacrylate and non-recycled methyl methacrylate, The content of the regenerated methyl methacrylate is 0.5 to 99.5% by mass, and the content of the non-regenerated methyl methacrylate is 0.5 to 99.5% by mass.

2. The methyl methacrylate composition according to claim 1, wherein The regenerated methyl methacrylate is regenerated methyl methacrylate derived from chemical recycling.

3. The methyl methacrylate composition according to claim 1 or 2, wherein The content of the regenerated methyl methacrylate is 5 to 40% by mass, and the content of the non-regenerated methyl methacrylate is 60 to 95% by mass.

4. The methyl methacrylate composition according to claim 1 or 2, wherein Also contains alkyl acrylate.

5. A method for producing a methyl methacrylate polymer, characterized in that: The method comprises the step of polymerizing the methyl methacrylate composition according to claim 1 or 2.

6. A methyl methacrylate polymer, characterized in that: The present invention is prepared by polymerizing the methyl methacrylate composition according to claim 1 or 2.

7. A methyl methacrylate polymer, characterized in that: The invention comprises structural units derived from recycled methyl methacrylate and structural units derived from non-recycled methyl methacrylate, wherein the content of the structural units derived from recycled methyl methacrylate is 0.5 to 99.5% by mass, and the content of the structural units derived from non-recycled methyl methacrylate is 0.5 to 99.5% by mass.

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